Various prior art compounds have been synthesized and more specifically fluorinated to provide at least partially fluorinated organic compounds having high degrees of heat stability. For instance, in U.S. Pat. No. 2,653,912, compounds are disclosed which are not substituted on the same or adjacent carbon atoms with hydrogen and fluorine. Such compounds include alpha(x trifluoromethylphenyl)beta(y trifluoromethylphenyl)tetrafluoroethane and similar compounds at column 2 of the patent. The compounds are synthesized by the dimerization of a monoaryl compound to produce the multiple aryl compounds of the patent. The compounds are useful as dielectric compositions, plasticizers for resins, heat transfer agents, hydraulic fluids and similar uses where elevated temperature stability and avoidance of chemical deterioration are necessary. The patent teaches that optimum stability is derived when the composition is hydrogenated at low pressure to remove unsaturated linkages.
U.S. Pat. No. 3,440,277 discloses various substituted fluorinated biphenyl compounds, particularly those substituted in the 3,3',4,4' positions. The compounds typically have radicals attached to the aromatic ring comprising carboxyl, bromine or hydrogen. The compounds have good heat stability and stability in the presence of oxygen and can be utilized as intermediates in the preparation of polymeric resins and oils.
Compound aromatic ring compounds are also known to be fluorinated as in U.S. Pat. No. 2,459,780 wherein various compounds, including perfluoroperhydrophenanthrene, are indicated as having utility as high temperature heat transfer media because of their non-flammability and stability to heat and oxidation.
The use of such fluorocarbon materials for vapor phase soldering is disclosed in RE No. 30,399 which describes the soldering of electronic components in the vapor of a boiling liquid comprising a fluorocarbon. The patent teaches that various FREON.RTM. compounds are useful as vapor phase soldering fluids.
U.S. Pat. No. 4,173,573 discloses a method for condensing orthoxylene with acetaldehyde to produce 1,1-bis(3,4-dimethylphenyl) ethane.
U.S. Pat. No. 4,549,686 discloses that perfluoroperhydrophenanthrene is a viable composition for utilization in vapor phase soldering wherein the compound has a boiling point of approximately 215.degree. C. and is useful on solders having a tin-lead composition wherein the tin content is in the range of 55-80%, the remainder comprising lead.
Japanese Published Patent Application No. 72 11,748 of Apr. 12, 1972 Kato, et al. assigned to Asahi Chemical Industry Co. Ltd. discloses the production of 1,1-diarylethanes from m-xylene and formaldehyde or paraacetaldehyde using an acid catalyst.
A. K. Barbour, et al. in Journal of Applied Chemistry Vol. 2, pp. 127-133 (1952) disclosed the cobalt trifluoride fluorination of various diaryl compounds to produce room temperature, solid fluorinated compounds, including (C.sub.6 F.sub.11 CF.sub.2 CF.sub.2).sub.2 CF.sub.2 and (C.sub.6 F.sub.11 CF.sub.2 CF.sub.2 CF.sub.2).sub.2.